1. Field of the Invention
The present invention relates to an ink container, and more particularly, to an easily fabricated ink container with a fixed piece, fixed pressure modulating mechanism.
2. Description of the Prior Art
The prior art ink container uses a flat spring within an air bag as a pressure modulating mechanism, as disclosed in U.S. Pat. No. 5,409,134. The flat spring must be installed within the air bag, so that the air bag has a somewhat complicated structure. This results in the wasting of much time when fabricating the ink container.
It is therefore a primary objective of the present invention to provide an ink container with a pressure modulating mechanism that is easy to fabricate, and that keeps pressure within the ink container lower than pressure of external air.
According to the claimed invention, the ink container comprises a casing and an ink reservoir. An air bag is set within the ink reservoir for pressure modulation, an air vent enabling air to enter or exit the air bag. The ink reservoir further includes a fixed piece, a helical spring and a restraining plate. The fixed piece has a first fixed surface fixed inside the casing and a second fixed surface. The helical spring has a first end connected to the second fixed surface and a second end. The restraining plate has a first surface connected to the second end of the helical spring and a second surface pressing on the air bag to clamp the air bag between the second surface of the restraining plate and the casing. Ink within the ink container flowing out of the ink outlet causes pressure within the ink container to drop. The air bag expands by accepting external air through the air vent, and the helical spring presses on the air bag by way of the restraining plate to keep the pressure within the ink container lower than the pressure of external air.
It is an advantage of the present invention that it is easily fabricated and retains precision of operation of the pressure modulating mechanism. Furthermore, the present invention reduces production costs and retains quality printing.
These and other objectives and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.